arch/arm/include/asm/sync_bitops.h

   1 #ifndef __ASM_SYNC_BITOPS_H__
   2 #define __ASM_SYNC_BITOPS_H__
   3
   4 #include <asm/bitops.h>
   5
   6 /* sync_bitops functions are equivalent to the SMP implementation of the
   7  * original functions, independently from CONFIG_SMP being defined.
   8  *
   9  * We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But
  10  * under Xen you might be communicating with a completely external entity
  11  * who might be on another CPU (e.g. two uniprocessor guests communicating
  12  * via event channels and grant tables). So we need a variant of the bit
  13  * ops which are SMP safe even on a UP kernel.
  14  */
  15
  16 #define sync_set_bit(nr, p)             _set_bit(nr, p)
  17 #define sync_clear_bit(nr, p)           _clear_bit(nr, p)
  18 #define sync_change_bit(nr, p)          _change_bit(nr, p)
  19 #define sync_test_and_set_bit(nr, p)    _test_and_set_bit(nr, p)
  20 #define sync_test_and_clear_bit(nr, p)  _test_and_clear_bit(nr, p)
  21 #define sync_test_and_change_bit(nr, p) _test_and_change_bit(nr, p)
  22 #define sync_test_bit(nr, addr)         test_bit(nr, addr)
  23 #define sync_cmpxchg                    cmpxchg
  24
  25
  26 #endif